Anti-Extravasation Catheter

ABSTRACT

The disclosed devices and methods provide for the minimization of fluid extravasation during use of infusion catheters such as peripherally inserted central catheters and central venous catheters. The anti-extravasation catheter allows a surgeon to drain fluids from soft tissue surrounding an infusion site while also providing fluid inflow to a patient.

This application is a continuation of U.S. application Ser. No.14/178,094, filed Feb. 11, 2014, now U.S. Pat. No. 10,456,510, which isa continuation of U.S. application Ser. No. 13/746,659, filed Jan. 22,2013, now U.S. Pat. No. 8,647,322, which is a continuation of U.S.application Ser. No. 11/585,716, filed Oct. 24, 2006, now U.S. Pat. No.8,357,126.

FIELD OF THE INVENTIONS

The inventions described below relate to the field of catheters and morespecifically, to catheters inserted into the central venous system.

BACKGROUND OF THE INVENTIONS

An infusion catheter, such as a peripheral intravenous catheter, is athin flexible tube that is inserted into a peripheral vein, usually inthe bend of the arm of a patient.

Once inserted, the infusion catheter is threaded along the peripheralvein with the tip ideally positioned for infusion of fluids where theycan be quickly diluted. Peripheral catheters as well as other types ofcatheters including peripherally inserted central catheters, centralvenous catheters and Hickman lines can remain in place for extendedperiods of time within a patient (up to six months). Infusion cathetershave been available for many years and are typically used to administerfluids such as parenteral nutrition, chemotherapy, vasopressor(adrenalin-like medications), antibiotics and other hypertonic/causticsolutions. These catheters may also be used for blood draws. The use ofsuch catheters avoids the complications associated with the directpuncture of the central venous circulation system. However, using aperipherally inserted central catheter to administer fluids to a patientis not without its drawbacks.

A common problem with the infusion of solutions into a patient isextravasation. Extravasation is the collection of interstitial fluidsuch as blood, nutritional fluids or medications into tissue surroundingan infusion site. Fluid escaping into the soft tissues surrounding theinfusion site can have adverse effects on the patient. Some of theseeffects include the forming of blood clots in veins (thrombophlebitis),arterial injury, nerve injury, the compression of blood vessels andnerves and infection.

Extravasation of certain medications can also lead to other injuriescommonly referred to as “IV burns.” Leakage of cytotoxic drugs,intravenous nutrition, solutions of calcium, potassium, bicarbonate andeven dextrose solutions outside the vein can cause skin necrosis. Othercomplications may include scarring around tendons, nerves and joints,especially on the dorsum of the hand or in the antecubital region.Extravasation may even cause skin loss above the area of injury and mayrequire skin grafting.

In cancer treatment, accidental extravasation is a feared complication,especially from drugs such as the anthracyclines, mitomycin,vincristine, and vinoorelbine, which are examples of vessicant drugs.Vessicant drugs cause tissue destruction upon infiltration. In thiscontext, extravasation is the unintended presence of a vessicant outsidethe vascular bed or vasculature.

Accidental extravasation has been estimated to occur in up to 6% of allpatients receiving chemotherapy. Chemotherapeutic agents, such as theanthracyclines, are especially likely to cause severe tissue damage onextravasation. The tissue injury may not appear for several days or evenweeks, but when it appears it may continue to worsen for months, due todrug recycling into adjacent tissue.

The danger of the adverse effects as well as kinks or clogs in thecatheter may require catheters to be removed from a patient andreinserted in another location. Furthermore, extravasation may result inlonger recovery time, pain and discomfort in patients. Because of theeffects caused by extravasation, devices and methods are needed toreduce extravasation caused by the use of infusion.

SUMMARY

The devices and methods shown below provide for the minimization offluid extravasation during use of infusion catheters includingperipheral catheters and central venous catheters. Theanti-extravasation catheter allows a surgeon to drain fluids from softtissue surrounding an insertion point or an infusion site while alsoproviding fluid inflow to a patient.

The anti-extravasation catheter comprises a multi-lumen flexible tubecharacterized by a distal end, a proximal end, a proximal portion and adistal portion. The proximal end of the tube is provided with fluidports, a manifold and other means of controlling the flow of fluidinside the tube. The distal portion of the tube is provided with one ormore outflow holes. The proximal portion of the tube is provided with aplurality of drainage apertures. Each drainage aperture communicateswith one or more drainage lumens inside the tube, thereby allowing fluidto drain from the tissue surrounding the insertion point of the catheterto sinks or vacuum sources located outside the patient. When theanti-extravasation catheter is disposed within the patient, the drainageholes are placed in fluid communication with tissue outside of theinsertion site. The anti-extravasation catheter allows a physician toadminister solutions to the patient while reducing the amount of fluidextravasation occurring in tissue surrounding the insertion point nearthe site of infusion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a patient with an anti-extravasation catheter inserted into aperipheral vein.

FIG. 2 is a cross-sectional view of the anti-extravasation catheter.

FIG. 3 is a sectional view of the proximal portion of the catheterwherein the drainage apertures are comprised of a pattern ofsubstantially circular fenestrations.

FIG. 4 is a catheter wherein the drainage aperture comprises alongitudinal channel.

FIG. 5 is an anti-extravasation catheter with an outer sleeve.

FIG. 6 is a side view of an anti-extravasation catheter with the outersleeve in use.

FIG. 7 illustrates an anti-extravasation catheter with an over-pressurevalve.

FIG. 8 illustrates the anti-extravasation catheter with the fluidmanagement system comprising a dissolvable plug disposed within thedrainage lumen.

FIG. 9 is a sectional view of the catheter of FIG. 8.

FIG. 10 illustrates the anti-extravasation catheter as part of anirrigation system.

DETAILED DESCRIPTION OF THE INVENTIONS

FIG. 1 is a patient 1 with an anti-extravasation catheter 2 insertedinto a peripheral vein 3. The anti-extravasation catheter comprises atube 4 having a central lumen 5 (shown in phantom) extending from theproximal end to the distal end. The tube has a length and an outerdiameter suitable for extending from an insertion point 6 on a patientto a treatment/infusion site 7. The insertion point is the place wherethe catheter is inserted in a patient. The infusion site is the area inthe body where the catheter infuses a fluid. A peripheral intravenouscatheter typically comprises a shorter tube (a few centimeters long)inserted through the skin into a peripheral vein. In the case of aperipherally inserted central catheter, the tube will be sized anddimensioned to extend from a peripheral insertion point to the centralvenous system including the superior vena cava or the right atrium. Whenthe infusion catheter is a central venous catheter, the tube is sizedand dimensioned to extend from a subclavian, internal jugular or afemoral vein to the superior vena cava or right atrium. The tube isconstructed of a material suitable for insertion into the venous systemof a patient such as silicone, nylon, polycarbonate urethane,polyurethane, polydimethylsiloxane and polyethylene glycol.

The length of the tube 4 is characterized by a distal section 12 (thevenous section) and a proximal interstitial section 13 (the interstitialsection). The distal end of the tube may contain a hollow penetratingelement 14 in fluid communication with the central lumen 5 to facilitateinsertion of the catheter into the patient. The proximal (interstitial)section of the tube is provided with a plurality of drainage apertures15. The proximal section of the tube is placed in contact with tissue 16surrounding the insertion point and the peripheral vein 3 of the patientwhen the catheter 2 is disposed within the patient 1. The drainageapertures 15 are disposed in such a way that the apertures 15 are placedin fluid communication with tissue surrounding the insertion point whereinterstitial fluid collection may occur when the catheter is in use.Each drainage aperture 15 communicates with one or more drainage lumensdisposed within the tube, thereby allowing fluid to drain from thetissue surrounding the insertion point to a vacuum source or sinkslocated outside the patient in fluid communication with the drainagelumens.

The proximal end of the tube is provided with a manifold or hub 17. Thehub is in fluid communication with the central lumen and the drainagelumens. The hub is adapted for coupling to a vacuum source 18 and fluidsource 19. The fluid source is placed in fluid communication with thecentral lumen of the catheter through the hub to facilitate the flow offluids into the patient. The vacuum source is placed in fluidcommunication with the drainage lumens to facilitate removal ofinterstitial fluid. A control system 20 may be operably connected to thefluid source to deliver fluid and to the vacuum source to removeinterstitial fluid by activating the vacuum source. Interstitial fluidis removed through one or more drainage apertures in fluid communicationwith the drainage lumens and the vacuum source. The control system mayalso be provided with a display 21 was well as an audio 22 and/or visual23 warning system that indicates when extravasation is occurring.

FIG. 2 is a cross-sectional view of the anti-extravasation catheter. Asseen in FIG. 2, the tube 4 comprises an inner tube 24 and an outer tube25 disposed about the outer tube and one or more ribs 26 extendingbetween the inner tube and outer tube. The inner tube, the outer tubeand the plurality of ribs bound one or more drainage lumens 27 disposedbetween the inner tube and the outer tube that extend longitudinallyalong the tube 4. Drainage apertures 15 are in fluid communication withone or more drainage lumens disposed within the tube.

Drainage apertures 15 may comprise a variety of patterns orconfigurations that allow for the effective removal of interstitialfluid. The size and pattern of the drainage apertures can be used toregulate fluid removal. FIG. 3 is a view of the proximal portion of thetube 4 wherein the drainage apertures are comprised of a patternsubstantially circular fenestrations 28. The tube 4 has one or moredrainage lumens disposed within the tube and running longitudinallyalong the catheter tube. A plurality of ribs 26 project from the innertube 24 to the outer tube 25 forming the plurality of drainage lumens27. Substantially circular fenestrations are disposed along the proximalportion of the outer tube. Each substantially circular fenestrationcommunicates with one or more drainage lumens 27 disposed within thetube.

FIG. 4 is a sectional view of the proximal portion of the catheterwherein the drainage apertures are comprised of a plurality oflongitudinal channels 29. The tube 4 has one or more drainage lumens 27disposed within the tube and running longitudinally along the cathetertube. A plurality of ribs project from the inner tube 24 to the outertube 25 forming the plurality of drainage lumens 27. Longitudinalchannels are disposed along the proximal portion of the outer tube muchlike a Blake's drain. Each longitudinal channel communicates with one ormore drainage lumens 27 disposed within the tube.

FIG. 5 is an anti-extravasation catheter with an outer sleeve. A secondtube or outer sleeve 30 is disposed over the outer diameter of thecatheter tube to limit exposure of the drainage apertures to the tissuesurrounding the insertion point. A first portion 31 of outer sleeve ispartially disposed about the proximal section (interstitial portion) ofthe catheter disposed within the patient. A second portion 32 of theouter sleeve is disposed about that proximal section of the catheterthat is not inserted into the patient. Use of one or more outer sleeves30 limits exposure of the drainage apertures to the tissue surrounding16 the insertion site. This regulates the amount of fluid that can drainfrom the tissue.

FIG. 6 is a side view of the anti-extravasation catheter 2 with thesleeve 30 in use. The catheter is disposed within the peripheral vein ofthe patient. The outer sleeve 30 is disposed over the outer diameter ofthe tube 4 to limit exposure of the drainage apertures to the tissuesurrounding the insertion site. The first portion 31 of outer sleeve isdisposed about that portion of the proximal section of the catheterdisposed within the patient. The second portion 32 of the outer sleeveis disposed about the proximal section of the catheter that is notinserted into the patient. The sleeve 30 regulates the exposure of thedrainage apertures to the tissue surrounding the insertion point. Tissue16 surrounding the insertion point and peripheral vein 3 may containextravasated fluid. The drainage apertures 29 allow this fluid to drainfrom the tissue and use of the sleeve regulates fluid removal.

The anti-extravasation catheter in FIG. 6 is part of a complete fluidmanagement system 33 comprising infusion pump 34, fluid source 19,vacuum pump 35, vacuum source 18 or sink, and control system 20. Thecontrol system may be provided with the display 21, the audio alarmsystem 22 and/or the visual alarm system 23. The alarm systems areactivated when extravasation occurs during the infusion of medicinesinto the patient 1 The alarm can be triggered by a pressure transducer36 operably connected to the control system and placed in fluidcommunication with one or more drainage lumens. Drainage apertures mayalso be disposed along the substantial length of the tube when thecatheter is part of the complete fluid management system or whenmultiple sleeves are used. When fluid pressure in the drainage lumenexceeds a safe threshold of pressure the control system can activate avacuum pump located outside and remove fluid from the tissue surroundthe infusion site.

FIG. 7 illustrates the anti-extravasation catheter 2 with anover-pressure valve 37. The valve is operably disposed within the hub 17and is placed in fluid communication with the drainage apertures 15through the drainage lumens 27 in the tube 4. The over-pressure valve isa relief valve comprising a flexible closure member 39 having a springconstant sufficient to press the closure member against the valve seat40 surrounding the drainage lumens 27 until pressure exceeds apredetermined safe threshold. The closure member is an annular membraneand member may be manufactured from a suitable polymer. The proximalsection of the closure member 39 is coupled to the hub wall while thedistal section presses against the valve seat occluding the drainagelumens 27. The valve allows the drainage lumen 27 in the device to opento the vacuum source and drain extravasated interstitial fluid fromtissue 16 when pressure from the fluid exceeds the predeterminedpressure threshold. The valve also acts as a barrier to outsidecontaminants. When fluid pressure in the drainage lumen 27 exceeds asafe threshold, such as a pressure in the range of approximately 1 mm/Hgto about 20 mm/Hg, the valve 37 opens to remove fluid from the tissuesurrounding the insertion point 6 and the infusion site.

FIG. 8 illustrates the anti-extravasation catheter 2 with the fluidmanagement system comprising a dissolvable plug 42 disposed within thedrainage lumen. The catheter in FIG. 8 is shown with longitudinalchannels 29 and outer sleeve 30. In a fluid management system comprisinga dissolvable plug 42, the drainage lumens 27 of the anti-extravasationcatheters illustrated in FIGS. 1 through 8 are filed with a dissolvableplug 42 comprising materials that dissolve when the materials come incontact with therapeutic agents being infused into the patent. Thedissolvable plug may comprise materials such as starches, gelatins,lactose, sucrose, sugars, or cellulose. The dissolvable plug may becoated with a water-resistant polymer or polysaccharide coating as well.The drainage apertures (longitudinal channel 29) disposed on the tubeare placed in fluid communication with tissue surrounding the insertionpoint when an anti-extravasation catheter is disposed within a patient.Should extravasation of the infused medications occur in the tissuesurrounding the insertion point, the infused medications will be placedin contact with the dissolvable plug 42 disposed within the drainagelumens 27. This contact or exposure will cause the dissolvable plug 42within the drainage lumens to dissolve, opening the drainage lumens andallowing interstitial fluid to drain from the tissue.

FIG. 9 is a sectional view of the tube 4 with the dissolvable plug. Thetube 4 has one or more apertures and one or more drainage lumens 27disposed within the tube and running longitudinally along the cathetertube. A plurality of ribs 26 project from the inner tube 24 to the outertube 25 forming the plurality of drainage lumens 27. Longitudinalchannels are disposed along the proximal portion of the outer tube muchlike a Blake's drain. Each longitudinal channel communicates with one ormore drainage lumens 27 disposed within the tube.

FIG. 10 illustrates the anti-extravasation catheter as part of anirrigation system. Certain therapeutic solutions used in chemotherapycan have detrimental effects on non-cancerous tissue. Flushing andevacuating dangerous infusates may be required should extravasationoccur. In an anti-extravasation catheter with an irrigation system, theanti-extravasation catheter of FIGS. 1 through 9 is provided with hub 17that is suitable for coupling to therapeutic fluid source 19, vacuumsource 18 and an antidote or dilution source 43. An antidote is acompound that blocks or attenuates the local tissue toxicity caused by atherapeutic fluid or agent. The vacuum source and dilution source areplaced in fluid communication with one or more drainage lumens throughthe hub 17. Thus, the drainage lumens can function as inflow and/oroutflow lumens. Pressure transducer 36 is operably connected to controlsystem 20 and the central lumen of the tube 4. The transducer 36 is ableto measure pressure in the vein of the patient. Other sensors that maydetect extravasation may be provided with the anti-extravasationcatheter and operably coupled to the catheter including electricalimpedance sensors, Ph sensors, optical sensors or tissue temperaturesensors. (The infiltration of an infusate into interstitial tissue mayresult in one or more changes in impedance, Ph or temperature.)

Extravasation can result from a thrombosed or collapsed vein 44. Acollapsed vein will cause a pressure increase within the vein of thepatient due to the backflow of an infusate. When a pressure increaseexceeding an acceptable threshold is detected by pressure transducer 36,the control system 20 may operate a pump operably coupled to thedilution source to flush the surrounding tissue. Tissue 16 is flushedusing the fluid from the dilution source that is placed in fluidcommunication with the tissue through one or more drainage lumens andone or more drainage apertures. The control system can also operate thevacuum source to aspirate the interstitial fluid from the tissue.Interstitial fluid is removed through one or more drainage apertures influid communication with the drainage lumens and the vacuum source. Thecontrol system can be programmed to perform cycles of infusion andaspiration to more completely dilute and remove harmful agents from thesoft tissue surround the insertion point of the catheter. A display 21as well as an audio 22 and/or visual 23 warning system that indicateswhen extravasation is occurring may also be provided with the controlsystem.

Current prior art catheters used in chemotherapeutic sessions do notprovide for the removal of interstitial fluid while simultaneouslyinfusing therapeutic agents into a patient. The anti-extravasationcatheter 2 is especially suitable for the infusion of therapeutic agentsused in chemotherapy. When the catheter is in use, the physicianprovides the anti-extravasation catheter 2 with at least one drainageaperture 15 disposed on the proximal portion of the catheter. Thecatheter is inserted into the vein of a patient at the insertion point6. The catheter 2 extends from the insertion point to the infusion site7 when functionally disposed with the patient 1. The catheter 2 isdisposed inside the patient 1 in such a way that the drainage aperture15 is placed in fluid communication with tissue 16 surrounding the vein3 and the insertion point 6.

The catheter 2 is operably connected to a therapeutic solution/fluidsource 19 and a vacuum source 19 through the hub 17. Duringchemotherapy, the therapeutic solution is infused into the patientthrough the catheter. During the infusion, extravasation may occur byfluid leaking from the infusion site into tissue surrounding the veinand the insertion point. This extravasated fluid is drained from tissuesurrounding the catheter insertion point and the vein 3 during achemotherapeutic session through the drainage aperture. The tissue 16may also be treated by an antidote that is provided through the apertureif necessary.

While the preferred embodiments of the devices and methods have beendescribed in reference to the environment in which they were developed,they are merely illustrative of the principles of the inventions. Otherembodiments and configurations may be devised without departing from thespirit of the inventions and the scope of the appended claims.

We claim:
 1. An anti-extravasation system comprising: a catheter havinga length and an outer diameter suitable for extending from a peripheralvein insertion point on a patient to a treatment site, said cathetercharacterized by an elongated venous section located distal to aninterstitial section and comprising: an inflow lumen; at least onedrainage lumen; and a plurality of apertures disposed in theinterstitial section of the catheter, said apertures in fluidcommunication with the drainage lumen and adapted to drain fluid fromtissue surrounding the insertion point when the catheter is operablydisposed within the patient; wherein the venous section of the cathetercomprises an outer surface and is structured to prevent fluidcommunication between the outer surface of the venous section and thedrainage lumen; and a hub proximal to the interstitial section andplaced in fluid communication with the inflow lumen and the drainagelumen.